Discussions

If you decide to put the piezo pickup inside the uke (my personal favourite) drill the hole for the wire through the center of the plastic stap button on the bottom of the instrument, therfore no drilling holes through the wood body of the instrument.

Follow the step above. You can get one of those piezo elements out of any talking/musical greeting card and from many cheap toys (i.e. McDonald's Happy Meal Toys).

I do NOT reccomend continuing on to drill holes in your instrument. Instead use a thin double-sided tape to stick the buzzer on the OUTSIDE of the instrument near the bridge. You may have to move it around to find the best sound. Then, get yourself a bottlecap that fits over the buzzer. Pad the inside of the cap with cotton, felt or hot glue and then use it to cover the buzzer. OR just buy one of these (common at music stores): http://www.theguitarfiles.com/product_id-1303.html .